Battery Power Delivery Module

ABSTRACT

A system and method for digital management and control of power conversion from battery cells. The system utilizes a power management and conversion module that uses a CPU to maintain a high power conversion efficiency over a wide range of loads and to manage charge and discharge operation of the battery cells. The power management and conversion module includes the CPU, a current sense unit, a charge/discharge unit, a DC-to-DC conversion unit, a battery protection unit, a fuel gauge and an internal DC regulation unit. Through intelligent power conversion and charge/discharge operations, a given battery type is given the ability to emulate other battery types by conversion of the output voltage of the battery and adaptation of the charging scheme to suit the battery.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Application claims priority to U.S. Provisional PatentApplications, Ser. No. 60/868,851, filed Dec. 6, 2006, and titled“Distributed Solar Array Monitoring, Management and Maintenance,” Ser.No. 60/868,893, filed Dec. 6, 2006, and titled “Distributed PowerHarvesting System for Distributed Power Sources,” 60/868,962, filed Dec.7, 2006, and titled “System, Method and Apparatus for ChemicallyIndependent Battery,” Ser. No. 60/908,095, filed Mar. 26, 2007, andtitled “System and Method for Power Harvesting from Distributed PowerSources,” and Ser. No. 60/916,815, filed May 9, 2007, and titled“Harvesting Power From Direct Current Power Sources,” the entire contentof which is incorporated herein by reference. Further, this Applicationis related to ordinary U.S. patent application Ser. No. 11/950,224,filed Dec. 4, 2007, titled “Current Bypass for Distributed PowerHarvesting Systems Using DC Power Sources,” patent application Ser. No.11/950,271, filed Dec. 4, 2007, titled “Distributed Power HarvestingSystems Using DC Power Sources,” patent application Ser. No. 11/950,307,filed Dec. 4, 2007 titled “A Method for Distributed Power HarvestingUsing DC Power Sources,” patent application Ser. No. 11/951,419, filedDec. 6, 2007, titled “Monitoring of Distributed Power Harvesting SystemsUsing DC Power Sources,” and patent application Ser. No. 11/951,485,filed Dec. 6, 2007, titled “Removal Component Cartridge for IncreasingReliability in Power Harvesting Systems,” and incorporates the entirecontent of these applications by this reference.

BACKGROUND

1. Field of the Invention

The present invention relates generally to power management, powerconversion and batteries and, more particularly, to power conversion forbatteries.

2. Related Arts

Most of the electronic devices today are configured for specific batterytypes and chemistries. The selection of which chemistry to use isusually based upon an assessment of, among other considerations, thedevice's environmental conditions and expected lifetime, and the priceof the battery at time of design.

Different batteries have different chemistries, each having their ownproperties, advantages and challenges. One conventional type of battery,that is used extensively especially in lower-end products, uses aNickel-Cadmium (Ni—Cd) chemistry. A Ni—Cd battery has numerous drawbacksand limitations: it allows only moderate energy density (45-80 Wh/Kg);has a high rate of self-discharge of approximately 20% per month; andrequires charging maintenance in the form of periodic charge/dischargecycles in order to prevent memory-effects which limit the usablecapacity of the battery. Furthermore, the compounds used in itsproduction are highly toxic and cause environmental problems. Cells ofthis chemistry have an output voltage of approximately 1.25 volts. TheNickel-Metal-Hydride (NiMH) chemistry is a variation of Ni-Cad andshares many of the Ni-Cad properties. It provides a slightly higherenergy density 60-120 Wh/Kg.

In the recent years, Lithium-ion (Li-ion) batteries have becomeprevalent, especially in devices which require high energy densitiessuch as laptops, medical devices and cell-phones. This chemistryprovides high energy density (150-190 Wh/Kg) and is environmentallyfriendly. However, it also suffers from numerous drawbacks. It has alimited life and after 300-500 cycles the battery's capacity drops to80% of the rated capacity. It has very low tolerance to overcharging,and if mistreated might become thermally unstable and hazardous. Inorder to maintain the battery's safety, it is essential to havecharge/discharge monitoring and protection circuits that preventover-discharge, monitor the charging process and stop the chargingbefore over-charge. Cells of this chemistry have a maximum outputvoltage of approximately 4.1V but will provide efficient power atapproximately 3.6V, and their voltage shouldn't drop under 2.5V-3V,depending on the kind of Li-ion used.

There is continuous progress in increasing the capacity of differenttypes of the Li-ion chemistry and new battery technologies, such asspinnel and Li-Polymer, keep emerging. These technologies, while similarto the regular Li-ion technology, may require adaptation of the hostingdevices due to slightly different voltages or charge procedures.

Finally, there are radically new battery technologies in the making,such as nano-tube based batteries, which hold the promise of much highercharge capacities. However, because these batteries will have electronicproperties different from the currently common batteries, the currentelectronic products would need an adaptation circuit in order to benefitfrom such batteries.

As set forth above, most electronic devices are configured for aspecific battery type. Locking the design of an electronic device intoone specific battery type prevents the device owners from enjoying thebenefits of new battery technologies, price reductions and otheradvances. In order to enjoy such benefits, the device must bere-designed in order to fit the new batteries. This is not desirable forthe buyer.

Furthermore, if problems are found in the battery management circuits, arecall may have to be made in order to fix the problem. Recalls, thathappen not infrequently, are costly to the device manufacturer.

Energy efficiency in analog conversion circuits is greatly dependantupon the current consumption. The conversion efficiency will usually behigh for the designed load and current consumption, but as the loadchanges the efficiency drops. Thus, if good energy efficiency isdesired, the conversion circuit must be specifically designed for thehost device. Building a voltage-converting circuit to fit many differentproducts and, thus, many different loads, is complicated and results ina large converter that is not suitable for a small battery.

SUMMARY

The following summary of the invention is included to provide a basicunderstanding of some aspects and features of the invention. Thissummary is not an extensive overview of the invention, and as such it isnot intended to particularly identify key or critical elements of theinvention, or to delineate the scope of the invention. Its sole purposeis to present some concepts of the invention in a simplified form as aprelude to the more detailed description that is presented below.

Aspects of the invention provide circuitry that may be incorporated inthe battery itself or outside of the battery. The circuitry isprogrammed to output the voltage required by the load, and monitors thepower drawn from the battery according to the battery's characteristics,e.g., type, temperature, age, shelf life, etc.

According to an aspect of the invention, an intelligent battery powerdelivery apparatus is provided, comprising: input terminals receivingpower from one or more battery cells; output terminal for providingpower to a load; and, a conversion module programmable to maintainoutput power characteristics at the output terminals according toprogrammed characteristics, and programmable to control power draw atthe input terminals according to programmed characteristics. Theconversion module may comprise an integrated circuit. The conversionmodule may comprise a DC/DC converter. The conversion module maycomprise a buck converter and a boost converter and wherein one of thebuck converter and the boost converter is engaged depending on the typeof the battery cell. The conversion module may further comprise abattery protection unit. The battery protection unit may comprise a fuelgauging unit for monitoring the state of charge of the one or morebattery cells. The conversion module may further comprise a currentsensor. The conversion module may further comprise telemetry terminalsfor communicating operation data. The apparatus may further comprise acasing, and wherein the conversion module and the one or more batterycells are housed within the casing and form an integral intelligentbattery. The conversion module may comprise a digital circuit, thedigital circuit comprising: a DC to DC voltage conversion unit; acurrent sense unit; a fuel gauge; and a central processing unit; whereinthe DC to DC voltage conversion unit is adapted to provide a desirablevoltage to the load, wherein the current sense unit is adapted to obtaina sensed current from the battery module and to utilize the sensedcurrent for functioning of the fuel gauge unit, wherein the fuel gaugeunit monitors a state of charge of the one or more battery cells andreports the state of charge to the central processing unit to preventovercharge or over-discharge of the one or more battery cells, andwherein the central processing unit manages the digital powerconversion. The conversion unit may comprise: a charge/discharge unit; abattery protection unit; and an internal DC regulation unit, wherein thecharge/discharge unit is adapted to provide over-current protectionduring discharge and to control charging schemes used by the intelligentbattery, wherein the battery protection unit is adapted to monitorvoltage, the sensed current and battery module charge and to alert thecentral processing unit of potentially hazardous conditions, and whereinthe internal voltage regulation unit regulates a voltage required byeach of the power management and conversion units. The conversion modulemay further comprise telemetry terminals for communicating with anoutside device, and wherein the central processing unit communicateswith the outside device via the telemetry port.

According to aspects of the invention, an intelligent battery isprovided, comprising: a casing; one or more battery cells housed withinthe casing; and a conversion circuit housed within the casing, theconversion circuit adapted to perform digital power conversion; whereinthe conversion circuit controls a voltage conversion to convert avoltage of the battery cells to a voltage level corresponding to loadrequirement, and wherein the conversion circuit controls a charging ofthe battery cells to provide an external DC voltage to the battery cellsaccording to charging requirements of the battery cells. The conversioncircuit may further comprise programming means enabling the conversioncircuit to provide output power characteristic of at least one of analkaline battery, a lithium ion battery, a metal hydride battery, aNickel-Cadmium battery, and a Nickel-Metal-Hydride battery, regardlessof the type of one or more battery cells housed within the casing. Theconversion circuit may comprise a digital integrated circuit. Theconversion circuit may comprise a charge/discharge unit; a batteryprotection unit; and an internal DC regulation unit.

According to aspects of the invention, a method for utilizing a firsttype battery in an application designed for a second type battery isprovided, the method comprising: converting a first power from the firsttype battery to a second power corresponding to the second type batteryusing digital power conversion; and converting a charging voltage from acharger corresponding to the second type battery to a charging voltageappropriate for the first type battery. The converting a first power maycomprise digitally converting the first power. The method may furthercomprise monitoring charging voltage applied to the first battery typeto protect from overcharging and under charging. The method may furthercomprise tracking battery status by monitoring charge condition in thefirst battery type.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, exemplify the embodiments of the presentinvention and, together with the description, serve to explain andillustrate principles of the invention. The drawings are intended toillustrate major features of the exemplary embodiments in a diagrammaticmanner. The drawings are not intended to depict every feature of actualembodiments nor relative dimensions of the depicted elements, and arenot drawn to scale.

FIG. 1 shows an integral intelligent battery according to aspects of theinvention.

FIG. 2 shows a modular intelligent battery according to aspects of theinvention.

FIG. 3 is a block diagram of components of an intelligent batteryaccording to aspects of the invention.

FIG. 4 is a plot of conversion efficiency versus load and shows acomparison between conversion efficiency of an analog conversion schemeand a digital conversion scheme.

FIG. 5 is a block diagram of a power management and conversion moduleused in an intelligent battery according to aspects of the invention.

DETAILED DESCRIPTION

Aspects of the present invention are directed to an intelligent batteryincluding one or more battery cells together with digital powermanagement and conversion electronics. The intelligent battery providesa substantially constant voltage required by the hosting device andmanages the charge/discharge operations. As a result, the hosting devicemay be simplified and different battery chemistries may be madecompatible with a particular hosting device.

In one aspect of the invention, a single package is provided, whichincludes both battery cell or cells and a power management integratedcircuit (IC). In one aspect of the invention, the package includes twoseparate modules, one including the battery cells and the otherincluding the power management IC such that the battery cells may bereplaced. The power management IC that is used may be included in thehost device, thus enabling the host device to use different batterycells. In one aspect, a safety circuit monitors the battery to preventmisuse and a charge circuit correctly charges the battery in an adequatemanner. Fuel-gauging may be used to provide data about thestate-of-charge of the battery and monitoring may be used to providedata about the state-of-health of the battery. The battery cells used invarious aspects of the invention may include chemical battery cells,fuel-cells, photovoltaic cells and the like.

Aspects of the invention also provide a method for utilizing a firsttype of battery in an application and a circuit that is designed for asecond type of battery. A power conversion scheme is used to convert thepower output from the first type of battery to the power that would beoutput from the second type of battery. The power conversion scheme maybe implemented digitally, due to its greater versatility and higherefficiencies over large load variations. Also, when a chargercorresponding to the second type of battery is being used to charge thefirst type of battery, the charging voltage is adjusted by the digitalpower conversion scheme to a level appropriate for charging the firstbattery. Digital power conversion schemes are used because they maintaina more uniform efficiency over a wider range of loads when compared toanalog power conversion schemes that are efficient only near theirdesign load.

FIG. 1 shows an integral intelligent power-converting battery 100,according to aspects of the invention. The battery 100 shown in FIG. 1includes one or more battery cells 102 and a power management andconversion unit 104 that are encased in the same casing. The battery 100also includes an anode terminal 106 and debug, telemetry and upgradeterminals 108 at the power management and conversion unit 104, and acathode terminal 110 at the one or more battery cells 102. The debug andtelemetry terminals 108 are optional.

The casing interfaces to external components and a host device via theanode 106 and the cathode 110 terminals. Through the anode and thecathode terminals 106, 110, energy from the battery may be supplied to ahosting device and external voltage may be applied to the battery inorder to charge the battery.

The power management and conversion unit 104 may provide the powerconversion, battery charge/discharge and communication functionality.The power management and conversion unit 104 may be implemented in a PCBwith discrete components soldered to it. Alternatively, the powermanagement and conversion unit 104 may be implemented in a singlecomponent IC.

The power management and conversion unit 104 controls the powerdelivered to the load and the power extracted from the batteries. As forthe power delivery to the load, unit 104 may be programmed with theparameters of the load, e.g., voltage and current requirements. Theprogramming can be done beforehand in the factory, and may also be doneby user programming or by “learning” the requirements from interactionwith the load. As for power extracted from the battery, here too unit104 may be programmed in the factory for a certain type of cell, but mayhave means for modifying this programming or for programming in thefield by user or by “learning” the cell's characteristics. For example,unit 104 could learn what battery-cell it is coupled to based on sensingthe output voltage, performing short-circuit for a very short time todetermine the maximum current, see how long it takes to drain to gathercapacity, etc. Using this information unit 104 provides the requiredoutput power to the load, but extracts power according to therequirements of the battery or cells. In this manner, any type ofbattery may be connected to any type of device.

The optional debug and telemetry terminals 108 are used for ascertainingstatus information about the intelligent battery or for providing theintelligent battery with operating instructions. Status informationabout the intelligent battery may be the state of charge (SoC) of theenclosed cell 102, state of health (SoH), internal temperature, andvarious statistics regarding the cell 102 that may be logged in thepower management and conversion unit 104. This statistics include dateof production, number of charge cycles to date, type of cells, celloutput voltage, and regulated output voltage. Operating instructions tothe intelligent battery may include requests for wanted regulator outputvoltage, current and voltage limiting, and various charge parameters.The charge parameters include the charging scheme parameters, amount ofcharge parameters and safety parameters. The charging schemes includeconstant current, constant voltage, trickle, and the like. The amount ofcharge parameters include the maximal and the minimal charge allowed.The safety parameters include the maximum allowed temperature.

Communications to and from the debug and telemetry terminals 108 may beimplemented by various protocols. In one aspect of the invention, anasynchronous serial communication bus may be used, in other embodimentssynchronous communications may be used such as SPI or I2C. Otherprotocols such as PMBus or SMBus may be used. Both point-to-point andbus topologies may be suitable for this type of communication. Thecommunication may be wireless, either in active form by use of IR or RFtransceivers, or in passive form by use of RFID or similar devices.

FIG. 2 shows a modular intelligent power-converting battery according toaspects of the invention. The modular intelligent battery 200 includestwo separate and connectable modules. A battery module 212 that includesthe battery cells 213 and a conversion module 214 that includes a powermanagement and conversion unit 215. In the modular intelligent battery200 shown in FIG. 2, replacement of the battery cell or battery cells213 is possible.

The battery module 212 includes an external battery cathode 217 andterminals 219 to the conversion module 214. The conversion module 214includes an external battery anode 221, optional debug, telemetry andupgrade terminals 223 and terminals 225 to the battery module 212. Thebattery module 212 and the conversion module 214 may be connectedthrough the terminals 219 and 225. The conversion module 214 may operateas unit 104 to ensure proper power output and proper power extractionfrom the battery module 212.

The conversion module may be implemented as application specific moduleor a generic module. When it is designed as application specific module,it is designed for a specific type of battery and a specific type ofload. In such a case, its input and output power requirements arepreprogrammed at the factory for the specific battery and specific load.On the other hand, if it is made as a generic module, means forprogramming different input and output power characteristics areprovided, so that the conversion module 214 may be connected to any typeof load and be used with any type of battery. Various methods forprogramming the required output and input may be implemented. Forexample, the unit may be coupled to a computer via a charger, USB, etc,and the required programming downloaded via the Internet. Also, meansmay be provided for a user to input a code when the battery type or loadis changed.

In the modular intelligent battery 200, the battery cells 212 may bereplaced when they malfunction or reach the end of their life. Themodular intelligent battery 200, however, may require a larger casing ormay be less reliable than the integral intelligent battery 100 of FIG.1.

FIG. 3 is a block diagram of components of an intelligent batteryaccording to aspects of the invention. FIG. 3 shows the coupling betweena battery module 302 including one or more battery cells and a powermanagement and conversion module 305 in an intelligent battery 300. Thetwo modules 302, 305 are coupled via voltage input terminals 308, 314.The voltage input terminals 308, 314 are respectively providing abattery Vcc and a battery ground. The battery module 302 and theconversion module 305 may also be connected by one or more sensors 312.These sensors may be temperature or pressure sensors but they may be anyother sensor deemed appropriate.

Voltage output terminals 310 and 316 are provided at the conversionmodule 305 and may also be used for charging the battery module 302.Optionally, a debug and telemetry terminal 318 may be present to providethe functionality discussed above.

In one aspect of the invention, the conversion module 305 includes an IC304 and external components. In FIG. 3, the external components arerespectively an inductor 306 and a capacitor 320. The integration of theelements into the IC 304 provides digital power conversion and permitsthe conversion module 305 to include fewer external components.

FIG. 4 is a plot of conversion efficiency versus load and shows acomparison between conversion efficiency of an analog conversion schemeand a digital conversion scheme. In FIG. 4, a load being supplied by abattery through a conversion module is shown on the horizontal axis andthe percent efficiency of the conversion is shown on the vertical axis.A load for which an analog conversion circuit is designed is shown at402. An efficiency curve 404 using an analog conversion and anotherefficiency curve 406 using a digital conversion are superimposed.

Analog power conversion schemes usually imply a linear controlalgorithm. These linear loops take a relatively long time to adapt tochanges in current consumption by the load or the host. Thus, if thehost suddenly starts to take more current, while the loop is adjusting,the voltage may drop. Large external capacitors and inductors are usedto prevent the drop and maintain the required voltage until the loopadjusts. When digital conversion is used, the loop feedback may not belinear. As a result the convergence time may be much faster. Thus,smaller components may be used. This could be beneficial in mobileapplications that require batteries.

As described above, and as depicted in FIG. 4, the analog conversioncircuitry is usually designed for a specific load such as the load 402.At this load, the analog conversion is quite efficient and theefficiency is shown at 95%. However, efficiency of the analog conversion404 drops at loads far from the design target load 402. As a result, itis difficult to design an efficient conversion circuit when the hostdevice is unknown.

On the contrary, when digital power conversion schemes are used,efficient conversion could be achieved for a wider array of loadconditions. As seen in FIG. 4, the efficiency curve 406 for digitalconversion stays near and above 95% efficiency over a large range ofloads. Therefore, an intelligent battery using digital power conversionis suitable for many different applications. The digital powerconversion circuits are managed by a CPU such as a CPU 514 shown in FIG.5.

FIG. 5 is a block diagram of a power management and conversion moduleused in an intelligent battery according to aspects of the invention.FIG. 5 shows internal units in an exemplary IC 504 of a power managementand conversion module according to aspects of the invention. The IC 504includes a charge/discharge unit 505, a DC to DC conversion unit 506, acurrent sense unit 508, a battery protection unit 510, a fuel gauge 512,the CPU 514, and an internal DC regulation unit 516. The IC 504 engagesin digital power management and conversion and therefore may operateover a large range of loads with substantially high efficiency.

The charge/discharge unit 505 is provided to prevent a load or a hostdevice from extracting too much energy from the battery cells duringdischarge and to provide over-current protection. The charge/dischargeunit 505 also disconnects the battery cells when they are empty in orderto prevent over-discharge. During charge, the unit 505 controls thecharging schemes used. Such schemes may be constant charge ratio,constant current, constant voltage and trickle charge. Because thecharging of the battery cells may be software controllable, otherschemes may also be implemented.

The DC to DC voltage conversion unit 506 is included to provide the hostdevice with the desired voltage. The conversion unit 506 may be a buck,boost, buck/boost or Cuk converter. The conversion may be donesubstantially inside the IC 504 with field effect transistors (FETs) anddrivers fabricated on the silicon substrate and only minimal externalcomponents such as an inductor and a capacitor may be used in additionto the circuits existing on the IC 504. The use of buck-boost orcascaded buck boost may be useful where the cell output voltage may dropbelow the desired output voltage. For example, if a Li-ion cell is usedand a 3.3V output voltage is desired, because fully charged Li-ion cellsprovide 3.6V to 4.1V, a buck conversion is needed when the battery isfully charged. The buck conversion provides a step down conversion from3.6V or 4.1V to the desirable 3.3V output voltage. However, Li-ion cellsmay drop to 2.5V and to fully utilize the charge contained in thesecells, a boost conversion is performed to raise the output voltage.

The battery protection unit 510 is included such that proper charge anddischarge conditions are applied. Monitoring of cell parameters such astemperature or pressure may be achieved via connection 526 to cellsensors located in a battery module such as the battery module 302 ofFIG. 3. Other critical data such as voltage, current and charge isobtained from the internal units within the IC 504. If the protectionunit 510 finds a potentially hazardous situation it may alert the CPU514. The CPU may take action to minimize the risk and it may also alertthe host device via the telemetry terminals.

The fuel gauging unit 512 may be present to monitor the state of chargeof the battery cell. This information is reported to the CPU 514 and maybe transferred to the host device. This information may also be used toprevent overcharge or over-discharge of the cell. Both overcharge andover-discharge conditions may prove dangerous to certain cellchemistries.

The current sense unit 508 is used to sense the current. The sensedcurrent is used for the functioning of both the protection unit 510 andthe fuel gauge unit 512. This current sensing may be done by monitoringthe voltage drop across a sense resistor such as a resistor 517 shown inFIG. 5. Current sensing may be achieved by using a current loop, or byusing other methods. The current sense unit 508 may be shared by boththe battery protection unit 510 and the fuel gauge unit 512, thuslowering costs and reducing board space.

The CPU 514 is used for digital power conversion management. The CPU 514may be implemented via a micro-processor, for ease of development, orvia a state-machine, which may provide lower current consumption. TheCPU 514 monitors various parameters, such as an input voltage 518 and anoutput voltage 520 to the IC 504, and controls the various internalunits of the IC 504 that are described above. The CPU 514 also maycommunicate with outside devices via the debug and telemetry port.

The internal voltage regulation unit 516 regulates the voltage requiredby each of the other internal units. The internal voltage regulationunit 516 may receive voltage from the battery cells, and may alsoreceive voltage from the host device in case the cells are exhausted andneed to be charged.

One exemplary aspect of the present invention may be embodied in anintelligent battery casing that looks like a regular AA battery, in amanner similar to the battery depicted in FIG. 1. This battery has aninternal Li-ion cell, which provides energy density greater than theenergy density of Ni—Cd or Ni-MH batteries. However, the cell providesan output voltage of 3.6V instead of 1.5V, and requires different chargeschemes. Part of the casing includes a small power management andconversion circuit. This circuit contains an IC and a few externalcomponents. The IC converts the voltage of the cell from 3.6V to 1.5V soit would seem like a regular Alkaline or Ni—Cd battery to any devicethat takes AA batteries. Providing an external DC voltage to theintelligent battery would cause the enclosed circuit to charge the cellin a manner favorable to Li-ion. This voltage could originate from aNi—Cd charger, a dedicated intelligent battery charger, or a simplevoltage source, for example, USB port of a computer. The describedintelligent battery provides the advantages of a Li-ion battery todevices that were designed for Ni—Cd AA batteries. Obviously, thisconversion may prove beneficial for other devices and batteries as well.

The present invention has been described in relation to particularexamples, which are intended in all respects to be illustrative ratherthan restrictive. Those skilled in the art will appreciate that manydifferent combinations of hardware, software, and firmware will besuitable for practicing the present invention. Moreover, otherimplementations of the invention will be apparent to those skilled inthe art from consideration of the specification and practice of theinvention disclosed herein. It is intended that the specification andexamples be considered as exemplary only, with a true scope and spiritof the invention being indicated by the following claims and theirequivalents.

1-20. (canceled)
 21. An apparatus, comprising: input terminals forreceiving power from a battery cell; an output terminal for providingpower to a load; one or more telemetry terminals for communicatingoperation data; and a conversion module programmable to maintain outputpower characteristics at the output terminal and to control power drawat the input terminals according to programmed characteristics, whereinthe conversion module uses the one or more telemetry terminals toreceive a date of production of the battery cell.
 22. The apparatus ofclaim 21, wherein the conversion module comprises an integrated circuit.23. The apparatus of claim 21, wherein the conversion module comprises aDC to DC converter.
 24. The apparatus of claim 21, wherein theconversion module comprises: a battery protection unit configured todetermine a hazardous condition of the battery cell; a fuel gauging unitfor monitoring a state of charge of the battery cell; and a currentsensor connected to at least one of the battery protection unit and thefuel gauging unit.
 25. The apparatus of claim 21, further comprising acasing, wherein the conversion module and the battery cell are housedwithin the casing.
 26. The apparatus of claim 21, wherein the conversionmodule comprises: a battery protection unit configured to determine ahazardous condition of the battery cell and alert a central processingunit; and the central processing unit configured to reduce a risk of ahazardous situation or to alert a host device drawing power from thebattery cell.
 27. The apparatus of claim 21, wherein the conversionmodule is configured to perform digital power conversion.
 28. Theapparatus of claim 21, wherein the conversion module uses the one ormore telemetry terminals to receive a number of charge cycles undergoneby the battery cell.
 29. The apparatus of claim 21, wherein theconversion module uses the one or more telemetry terminals to receive arequest for a desired output voltage of the battery cell.
 30. Theapparatus of claim 21, wherein the conversion module uses the telemetryterminals to receive charge parameters, and wherein the conversionmodule is configured to control charging of the battery cell based onthe charge parameters.
 31. The apparatus of claim 21, wherein the one ormore telemetry terminals are configured to communicate wirelessly. 32.The apparatus of claim 21, wherein the one or more telemetry terminalsare configured to communicate using an infrared transceiver.
 33. Theapparatus of claim 21, wherein the one or more telemetry terminals areconfigured to receive communications using a radio frequencyidentification (RFID) reader.
 34. A battery comprising: a casing; one ormore battery cells housed within the casing; one or more telemetryterminals; and a conversion module housed within the casing, theconversion module configured to use the one or more telemetry terminalsto receive a date of production of at least one of the one or morebattery cells, wherein the conversion module is programmable to maintainoutput power characteristics at an output terminal and to control powerdraw at input terminals according to programmed characteristics.
 35. Thebattery of claim 34, wherein the one or more telemetry terminals areconfigured to communicate wirelessly.
 36. The battery of claim 34,wherein the one or more telemetry terminals are configured tocommunicate using an infrared transceiver.
 37. The battery of claim 34,wherein the one or more telemetry terminals are configured to receivecommunications using a radio frequency identification (RFID) reader. 38.A method, comprising: configuring a power management unit to connect toa variety of battery cells; programming the power management unit tomaintain output power characteristics at an output terminal providingpower to a load according to at least one parameter of the load; andusing one or more telemetry terminals to receive a date of production ofa particular battery cell connected to the power management unit;programming the power management unit to control power draw at inputterminals receiving power from the particular battery cell based atleast on the date of production of the particular battery cell.
 39. Themethod of claim 38, further comprising: programming the power managementunit with a power conversion scheme that converts a first power outputof the particular battery cell to a second power output based on a load;and programming the power management unit with a charging scheme thatconverts a first charging voltage to a second charging voltage whencharging the particular battery cell.
 40. The method of claim 38,further comprising: receiving, by the one or more telemetry terminals,an infrared signal or radio frequency identification (RFID) signal froman RFID tag.